Bolt head identification

[Shaun Cooney]

Hi
Trying to identify is some bolts I have are high tensile

Markings on the head are:

TWL (Manufacturer)
M (Metric (it's M16))
50B (UNKNOWN)
Solid raised line (that goes right across the head)

I got the bolts when they were left in a field following the erection of a en electricity pylon. They're galvanised.
Any help appreciated as I can't find anything on the web.

Cheers

Shaun

 

[hotponyshoes]

50B is the older BS standard.
Equivalent EN10025 number would be a S355JR.

Unless it's for a specific application I would think any 8.8 bolt would be usable for the same thing

 

[seriesonewelder]

TWL = Thomas William Lench
The factory is now a housing estate

 

[Shaun Cooney]

50B is the older BS standard.
Equivalent EN10025 number would be a S355JR.

Unless it's for a specific application I would think any 8.8 bolt would be usable for the same thing

Ah right - I have quite a few and all new - so are wanting to use them in 8.8 'situations' if they're a similar. Today it was for a towbar but didn't want to use them until I knew what tensile strength they were
Shaun

 

[Agroshield]

50B is the older BS standard.
Equivalent EN10025 number would be a S355JR.

Could you be specific on the title and scope of the 'older BS standard' please?

As you know, EN100025 is the standard for structural steel. I do not think it has anything to say on fasteners.

From what I can see, the standard for 8.8 stuff is EN15048. You would need to find mention of 50B in its predecessor so that you are comparing apples with apples.

Hence, I do not think the 50B in the old structural standard has any relationship with the 50B on a bolt. For instance, a grade 8.8 bolt (800 MPa yield) is a lot better than S355 (355 MPa yield).

----

To the OP: if you know the bolt was destined for use in a pylon, try searching for specifications for the supply and erection thereof (via the power network/infrastructure companies, i.e. not the name that is on your electricity bill). That might give you something.

Edit:

Thinking about it further, I wonder if the bolts for pylons are pre-loaded ones, not 'normal' ones. A class of these are known as 'high strength friction grip' bolts. For a pylon subject to wind loads, the more rigid connection between members they offer might be required.

Have a sniff around BAPP's website (https://www.bapp.co.uk/) and maybe send them a picture of the head.

 

[Shaun Cooney]

Could you be specific on the title and scope of the 'older BS standard' please?

As you know, EN100025 is the standard for structural steel. I do not think it has anything to say on fasteners.

From what I can see, the standard for 8.8 stuff is EN15048. You would need to find mention of 50B in its predecessor so that you are comparing apples with apples.

Hence, I do not think the 50B in the old structural standard has any relationship with the 50B on a bolt. For instance, a grade 8.8 bolt (800 MPa yield) is a lot better than S355 (355 MPa yield).

----

To the OP: if you know the bolt was destined for use in a pylon, try searching for specifications for the supply and erection thereof (via the power network/infrastructure companies, i.e. not the name that is on your electricity bill). That might give you something.

Edit:

Thinking about it further, I wonder if the bolts for pylons are pre-loaded ones, not 'normal' ones. A class of these are known as 'high strength friction grip' bolts. For a pylon subject to wind loads, the more rigid connection between members they offer might be required.

Have a sniff around BAPP's website (https://www.bapp.co.uk/) and maybe send them a picture of the head.

Thank you - I'll give that a go :-)

 

[badabec]

The anally retentive rivet counters that own old Citroens call these bolts 'Citroen bolts'. I think they are confusing Citroen chevrons with what looks like a stylised conifer tree. Anyone any idea whose trademark or grade marking this is?
Thanks